Apparatus for manufacture of tubular projectiles

ABSTRACT

A plurality of tubular projectiles for use as fire extinguisher casings are simultaneously provided from a single piece of hollow cylindrical stock by techniques which involve rotating the cylindrical stock about its longitudinal axis and spinning the stock material inwardly at a point longitudinally central of each pair of projectiles to be provided while axially loading the stock to provide uniform thickness of material in the spinning area. The tubular stock is rotatably supported by formed mandrel apparatus in cooperation with a plurality of fluid operated actuators and material spinning is provided around the formed mandrel apparatus located within the hollow stock by a pair of rollers acting as another mandrel and having surfaces which conform to the formed surfaces of the interior mandrel apparatus, the rollers being movable over arcuate paths at the ends of a scissors apparatus which is also operated by a fluid controlled actuator. One end of a casing is closed by hot spinning or welding techniques and the formed end of a casing has a valve affixed thereto and the casing is charged to provide a fire extinguisher.

United States Patent Huthsing, J r., deceased 1 Apr. 4, 1972 Charles K.Huthsing, Jr., deceased, late of Libertyville, III. by Evelyn N.l-luthsing, executrix [22] Filed: Feb. 28, 1969 [21] Appl.No.: 803,337

[72] inventor:

Primary Examiner--Frank T. Yost Attorney-Hill, Sherman, Meroni, Gross &Simpson [57] ABSTRACT A plurality of tubular projectiles for use as fireextinguisher casings are simultaneously provided from a single piece ofhollow cylindrical stock by techniques which involve rotating thecylindrical stock about its longitudinal axis and spinning the stockmaterial inwardly at a point longitudinally central of each pair ofprojectiles to be provided while axially loading [52] U.S.Cl ..72/82,29/1.2l, 113/ 120T the stock to provide uniform thickness of material inthe [51] Int. Cl ..B2ld 22/14 spinning area. The tubular stock isrotatably supported by [58] Field of Search ..29/ 1.21; 72/82, 83; 113/120'! formed n re ppa in oop ration with a plurality of fluid operatedactuators and material spinning is provided 56] Ref en Ci around theformed mandrel apparatus located within the hollow stock by a pair ofrollers acting as another mandrel and UNITED STATES PATENTS havingsurfaces which conform to the formed surfaces of the interior mandrelapparatus, the rollers being movable over ar- 5Ol547 7/1893 Thomson 2cuate paths at the ends of a scissors apparatus which is also 757,432 4/1904 Bates ..7 operated by a fluid controlled actuator. One end of acasing is 1353982 9/1920 Bally et 29/121 X closed by hot spinning orwelding techniques and the formed 81 4/1928 "72/82 X end of a casing hasa valve affixed thereto and the casing is 2,030,818 2/ 1936 Harter.........29/ l .21 X charged to provide a fire extinguishen 3,299,680 l/l967Thompson ..72/82 X 7 Claims, 11 Drawing Figures PATENTEDA R 4 I912 SHEET3 UF 4 MNn www

J TIIA NW m m PATENTEDAPR 41912 3.653240 SHEET U 0F 4 APPARATUS FORMANUFACTURE OF TUBULAR PROJECTILES BACKGROUND OF THE INVENTION 1. Fieldof the Invention This invention relates to the manufacture of tubularprojectiles and is particularly concerned with the method of anapparatus for providing a plurality of tubular projectilessimultaneously from a single piece of cylindrical stock and theprovision of fire extinguishers by the method and apparatus by which aplurality of fire extinguisher casings are provided simultaneously byspin forming techniques.

2. Description of the Prior Art Heretofore, the manufacture of aplurality of like tubular projectiles generally included cutting aplurality of hollow cylinders from tubular stock and individuallyforming the ends of the cylinders to the desired configurations. Foreach cylinder there was required a separate forming step for each areaof the cylinder which had a different formed configuration. It istherefore desirable in the manufacture of a large number of such formedtubular members that the number of steps per member be decreased to aminimum. In contrast to prior art techniques, the present inventionprovides for a decrease in the number of operations in forming tubularprojectiles to the desired shape by at least one forming step for eachtwo projectiles.

SUMMARY OF THE INVENTION Briefly, according to the present invention, aplurality of like tubular projectiles are simultaneously formed to theirdesired shapes by a material spinning technique which comprisesrotatably supporting an elongate piece of tubular stock on a mandrelhaving formed surfaces which partially define the desired shape of theprojectile, rotating the tubular stock about its longitudinal axis,applying a radial loading on the tubular stock in the area of the formedmandrels by wheels having formed surfaces which cooperate with thesurfaces of the mandrel to define the desired shape of the projectiles,and simultaneously loading the rotating tubular stock along itslongitudinal axis so that the section of the stock being formed betweenthe formed mandrel and the formed rollers is maintained at a uniformthickness. The resulting symmetrically shaped tubular elements areseparated for further processing to form a pair of fire extinguishercasings, the formed end being provided with an internal thread forengaging a fire extinguisher valve assembly and the other end beingsubjected to a step or a plurality of steps wherein it is closed andsealed.

The closing and sealing of the unformed end being provided by an endclosure which is welded to the body, or by a hot spinning process whichcloses the end of the body. After the fire extinguisher body has been soformed, the extinguisher is then charged.

It is therefore the primary object of the invention to provide new andimproved techniques for the manufacture of tubular projectiles.

Another object of the invention is to provide a new method and apparatusfor forming a plurality of tubular projectiles simultaneously.

It is yet another object of the invention to provide new and improvedmethods and apparatus for the manufacture of tubular projectilesemploying material spin forming techniques.

Still another object of the invention is to provide new and improvedmethods and apparatus for manufacturing fire extinguishers.

Yet another object of the invention is to provide new and improvedmethods and apparatus for manufacturing fire extinguishers by materialspin forming techniques including hot spinning to close the open end ofa tube.

BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and other objects andfeatures of the invention, its organization, construction and operationwill be best understood from the following detailed description taken inconjunction with the accompanying drawings in which:

FIG. 1 is a side elevational view in fragmentary section, of a pair ofsymmetrical tubular projectiles simultaneously fonned from a singlepiece of tubular stock in accordance with the principles of the presentinvention;

FIG. 2 is a sectional view of one of the projectiles of FIG. 1 after itsseparation from the other such projectile;

FIG. 3 is a sectional view of the apparatus of FIG. 2 as it appears uponreceiving the threads at one end thereof and which has been hot spun forclosure at the other end thereof;

FIG. 4 is a view similar to FIG. 3 showing the attachment of a valve tothe fire extinguisher body and the further processing of the hot spunend of the body, the cylinder being in a charged condition;

FIG. 5 shows an alternate form of a fire extinguisher wherein the end isclosed by welding techniques;

FIG. 6 is an elevational view of a machine for forming the structureshown in FIG. 1;

FIG. 7 is a top plan view of the apparatus of FIG. 6;

FIG. 8 is an end view of the apparatus shown in FIG. 6;

FIG. 9 is an operational diagrammatic representation of the apparatusillustrated in FIGS. 6-8;

FIG. 10 is a fragmentary view of a portion of the apparatus shown inFIG. 6, but in greater detail; and

FIG. 11 is a view similar to FIG. 10 showing details of a portion of theapparatus of FIG. 6.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1 there is generallyshown at 10 a pair of identically formed, and still joined, tubularprojectiles 19 and 20 which are defined by wall 11 and the spun formedwall portions 12- 14. Illustrated in phantom and superimposed over theapparatus of the projectiles is the original shape of the tubular stockwhich is greater in length tha apparatus 10 by the lengths of elementportions 21 and 23. Wall 11 of projectile l9 and of projectile 20 andthe formed wall sections joining these projectiles define three chambersections 15, I6 and 17. Phantom section 22 illustrates the degree ofspin forming between the outer periphery of the tubular stock and theformed periphery of section 14. It will also be appreciated that theprojectiles 19 and 20 are symmetrical about the longitudinal axis'oftube 10 and about the center line 18.

The two cylinders after being formed to the shape illustrated in FIG. 1are separated and appear as shown in FIG. 2. Chamber 16 of FIG. 1 hasnow been reduced to one half of its size and designated as chamber 26(the throat of the fire extinguisher) in FIG. 2. At this time end 27 ofthe projectile may be subjected to a finishing step in which the roughedges are finished smooth. Also at this time any rough edges on end 24may be finished smooth as determined by further steps of processing. Forexample, if the projectile 19 of FIG. 2 is to be processed as shown inFIG. 3, such rough edges need not be removed at this time.

The projectile illustrated in FIG. 3 shows the results of a hot spinningstep wherein the end 24 of FIG. 2 is heated to approximately 2,000 F.and the projectile is hot spun to a closed spherical surface asreferenced at 29. The projectile is then placed in a press while stillhot and end 29 is pressed inwardly to form the shape 30 having edge 31as shown in FIG. 4. After the projectile or casing has been so formed, avalve assembly 32 is fixed thereto at 27 and the extinguisher ischarged, character 15a symbolizing charging of the chamber.

As an alternative to hot spinning and pressing to form end 24 into shape29 and then shape 30 as discussed above, end 24 may have a plate 33 of adiameter substantially equal to the internal diameter of the projectilesas shown in FIG. 5. Plate 33 includes an outwardly curved section 34 andan annular ridge 35 on its outer periphery which lies adjacent end 24.Plate 33 is then welded as shown at 36 to sealingly affix plate 33 tocasing wall 11. At this time any rough edges may be finished at end 24,ridge 35 and weld 36. The projectile is then provided with a valveassembly and charged as discussed in regard to FIG. 4.

With the foregoing in mind, and referring now to FIGS. 6-11, there isillustrated apparatus for providing the symmetrical connected projectilestructures of FIG. 1.

The apparatus is generally shown at 100 as comprising a frame 101 havinga pair of rails 102 and 103 which are supported by a plurality of legstructures 104, 105, 106 and 107 which are in turn joined by members108, 109 and 110 to support the frame on a surface 111. Carried by theframe are a plurality of fluid operated (hydraulic or air) actuatordevices. These devices are: actuator 120 having mounting apparatus 121and an extensible piston rod 122; actuator 130 including mountingapparatus 131 and a hollow extensible piston rod 132; actuator 140including mounting apparatus 141 and having a hollow extensible pistonrod 142; actuator 150 including mounting apparatus 151 and an extensiblepiston rod 152; actuator 160 having mounting means 161 and an extensiblepiston rod 162; and another actuator similar to actuator 160, but notshown in the drawings.

Also shown in the drawings is formed mandrel apparatus including a shaft172 which extends through the hollow extensible piston rod 132 and asimilar shaft 182 which extends through the hollow extensible piston rod142 into the working area 200. Shaft 182 is connected to extensiblepiston rod 162 of actuator 160 by way of linkage 181. Similarly, shaft172 is connected by way of linkage 171 to the counterpart of actuator160.

Generally speaking, a piece of tubular stock is placed in the workingarea 200 and rotatably secured in place by a plurality of rollers236-239 which are part of the stock holding apparatus 226. Apparatus 226includes a pair of spaced-apart side plates 227 having arcuate sections228 in general conformity to the diameter of the stock, side plates 227being joined by rods 229 and 230 and pivotally joumalled at rod 231having a locking notch 235 therein. As apparatus 236 is pivoted to anupright working position, locking apparatus 232 having a handle 233 anda pin 234 which is biased inwardly by a spring 234 operates to engagepin 234 in notch 235. To remove the formed joined projectiles from themachine 100, handle 233 is pulled against the biasing of the spring 234to release pin 234 from notch 235 and free apparatus 226 for rotationabout rod 231.

With the tubular stock locked in operational position by apparatus 226the proper switches 194 of controller 193 are actuated and actuator 160and its unshown counterpart operate to position the two halves of themandrel apparatus in engagement within the tubular stock. Mandrel 180includes a formed head 185 which is extensible by way of shaft 182 intothe working area. Likewise, shaft 172 carries a similar formed head 185ainto the working area from the opposite direction. Head 185a hasattached thereto a projecting pin 203 to aid in defining the completedform of the joined projectiles and which is positioned within bore 202of head 185. Upon complete engagement of the mandrel heads 185, 185aactuators 120 and 150 are operated to lock the respective mandrel shafts172 and 182 into their forward extended positions, for example shaft 182includes a notch 183 therein for receiving the end of piston rod 152 ofactuator 150. The same is true with respect to actuator 120 and mandrelshaft 172.

After the mandrels are locked in operating position, actuators 130 and140 are operated to extend their hollow piston rods 132 and 142,respectively, toward the mandrel heads. This effects a rotationallocking of the tubular stock to the prime mover 190. Such engagement isefiected by a pair of arbors,for example arbor 181, which are connectedto the hollow extensible piston rods 132 and 142. Arbor 181 includes agear 183 having a portion 186 which is substantially the diameter of thetubular stock and which carries a ring of teeth 187'for engagement ofthe ends of the tubular stock as the arbor is moved against the stock.Arbor 181 includes a bearing 184 for joumalling a toothed shaft 198thereto. A second gear 199 is fixed for rotation with shaft 198 and ismeshed in a driving relationship with gear 183. Shaft 198 is connectedin driving relationship to prime mover 190 through belt 192 and pulleys191 and 195. Shaft 198 also includes a section 196 for extending drivingrotation to the arbor associated with actuator 130, the shaft 196 beingsupported by the frame at bearing 197. The mandrel heads 185 and 185ainclude bearings, for example bearing 201, which permits the head of themandrels to rotate with the tubular stock without affecting rotation ofthe mandrel shafts 172 and 182.

After the tubular stock has been locked into an operational.

against the tubular stock. The scissor-like apparatus comprises a pairof lever elements 214 and 215 which are spaced apart by rods 216 andpivotally connected to a cross member 218 of frame 101 at a pin 219. Asimilar set of elements referenced 216, 217 and 220 are pivotallyconnected to the frame on the opposite side of the machine. A fluidoperated actuator 210 having an extensible piston rod 212 is pivotallyconnected to the aforementioned spaced-apart levers by pins 211 and 213.The levers have ends which extend into the working area 200 and haverotatably secured thereto rollers 221 and 222 respectively by way of therespective pins 223 and 224.

Upon reaching the desired rotational speed, actuator 210 is operated toextend its piston 212 and radially load the tubular stock by the forceexerted by wheels 221 and 222. it should be noted that wheels 221 and222 have curved surfaces 225 which conform to and help define thedesired configuration of the projectile. In effect, wheels 221 and 222provide outer forming mandrels which cooperate with the inner mandrelsto define and form the desired shape of the projectiles.

Attention is invited that during the entire forming operation theactuators and maintain a constant force on the ends 24 and 25 of thetubular stock so that during the spinning process the stock is providedwith a continuous axial loading thereof so that the material in the areaof the mandrels is maintained at a substantially constant thickness.Accordingly, the length of the formed projectiles is less than thelength of the original tubular stock, e.g., sections 21 and 23 of FIG.1.

Upon completion of the desired deformation of the hollow tube, selectedones of switches 194 are operated so that the tube may be removed fromthe machine for further processing as hereinbefore set forth to providefire extinguisher apparatus. Operation of such switches effect atermination of rotation; releasing of the latches at actuators 120 andrelease of the ends of the tube by the teeth 187 upon operation ofactuators 130 and 140; and withdrawal of the mandrels by actuator andits counterpart.

Although the invention has been described and illustrated by specificexemplary embodiments, many changes and modifications will becomeapparent to one skilled in the art. For example, one may find itadvantageous to maintain the prime mover operative and provide a clutcharrangement disposed between the prime mover and the driver arbors;however, such changes and modifications should be included within thespirit and scope of the invention as defined in the appended claims.

The embodiments of the invention in which an exclusive property ofprivilege is claimed are defined as follows:

1. A machine for making tubular projectiles from a hollow cylindricaltube, comprising: a frame; means carried on said frame for rotatablysupporting the hollow tube; means for rotating the hollow tubecomprising a pair of fluid-operated means each including an extensiblehollow shaft, a pair of toothed wheels rotatably carried by therespective hollow shafts for engaging the ends of the tube, and meansfor rotating said toothed wheels; first and second mandrel means carriedon said frame including respective first and second extensible mandrelsand means for extending said first and second mandrels into the interiorof the tube; third mandrel means carried on said frame including atleast one third mandrel disposed externally of the tube adjacent theextended position of said first and second mandrels; means for forcingsaid third mandrel against the tube section between said first andsecond mandrels to deform the tube section; and means for continuouslyurging the ends of the tube toward each other during deformation of thetube to provide a constant wall thickness of the tube in the deformedsection.

2. The machine according to claim 1, wherein said first and secondmandrel means each comprises an extensible shaft including a groovetherein and wherein said machine further comprises first and secondfluid-operated means each including extensible shaft means forengagement with the respective groove for releasably latching saidshafts in their extended positions.

3. The machine according to claim 1, wherein said means for rotatablysupporting the tube comprises arcuate-shaped means pivotally carried onsaid frame for receiving the tube, first wheels carried by saidarcuate-shaped means, second wheels carried by said frame, the tubebeing placed in rotatable engagement with said first and second wheelswhen said arcuate-shaped means is pivoted to place the tube in a workingposition, and means for releasably latching said arcuateshaped means atthe working position of the tube.

4. A machine for making tubular projectiles from a hollow cylindricaltube, comprising: a frame; means carried on said frame for rotatablysupporting the hollow tube; means for rotating the hollow tube; firstand second mandrel means carried on said frame including respectivefirst and second extensible mandrels and means for extending said firstand second mandrels into the interior of the tube, said first and secondmandrel means each comprising an extensible shaft mounted on said framefor reciprocal movement; and a formed mandrel head rotatably carried byits respective shaft, said first formed head including a pin whichextends toward the second formed head, and said second formed headincluding a bore therein for receiving said pin when said shafts areextended, said first and second heads and said pin defining the desiredinner form of said tube; third mandrel means carried on said frameincluding at least one third mandrel disposed externally of the tubeadjacent the extended position of said first and second mandrels; meansfor forcing said third mandrel against the tube section between saidfirst and second mandrels to deform the tube section; and means forcontinuously urging the ends of the tube toward each other duringdeformation of the tube to provide a constant wall thickness of the tubein the deformed section.

5. The machine according to claim 4, wherein said third mandrel includesa shaped surface which conforms to the shape defined by said first andsecond heads and said pin.

6. A machine for making tubular projectiles from a hollow cylindricaltube comprising: a frame; means carried on said frame for rotatablysupporting the hollow tube; a pair of first fluid-operated means carriedon said frame, each of said first fluid-operated means including ahollow extensible shaft directed toward the hollow extensible shah ofthe other and a hollow toothed wheel rotatably secured to the hollowshaft, the ends of the tube being engaged by the teeth of the wheels formutual rotation therewith; means for rotating said tooth wheels; a pairof mandrels carried on said frame with their axes in co-axial alignmentwith the longitudinal axis of the tube and each of said mandrelsdirected toward the other and extending through respective ones of saidhollow shafts and toothed wheels, and including a shaft mounted forreciprocal movement along its axis, a formed head and means forcooperable engagement of said heads; a pair of second fluidoperatedactuators carried by said frame and including respective extensibleshafts individually connected to separate ones of said mandrel shaftsfor reciprocal movement of said mandrel shafts; means for releasablylatching said first and second mandrel shafts with their respectiveheads positioned adjacent one another within the tube; and means forminga third mandrel adjacent said first and second mandrel heads on theexterior of the tube carried by said frame, said third mandrel formingmeans including a pair of lever means pivotally connected to said frame,at least one wheel rotatably carried by each of said level means withthe axis of rotation of the wheels being generally parallel to thelongitudinal axis of the tube, and means for pivoting said lever meansand forcing said wheels against the rotating tube to spin from thematerial in the contacted area into a shape defined by said first andsecond heads and said wheels.

7. A machine for making tubular projectiles from a hollow cylindricaltube according to claim 6 wherein said means for pivoting said levermeans comprises third fluid-operated means including a body sectionconnected to one of said lever means and a shaft extensible from saidbody second connected to the other of said lever means to operated saidlever means in a scissor-like manner.

1. A machine for making tubular projectiles from a hollow cylindricaltube, comprising: a frame; means carried on said frame for rotatablysupporting the hollow tube; means for rotating the hollow tubecomprising a pair of fluid-operated means each including an extensiblehollow shaft, a pair of toothed wheels rotatably carried by therespective hollow shafts for engaging the ends of the tube, and meansfor rotating said toothed wheels; first and second mandrel means carriedon said frame including respective first and second extensible mandrelsand means for extending said first and second mandrels into the interiorof the tube; third mandrel means carried on said frame including atleast one third mandrel disposed externally of the tube adjacent theextended position of said first and second mandrels; means for forcingsaid third mandrel against the tube section between said first andsecond mandrels to deform the tube section; and means for continuouslyurging the ends of the tube toward each other during deformation of thetube to provide a constant wall thickness of the tube in the deformedsection.
 2. The machine according to claim 1, wherein said first andsecond mandrel means each comprises an extensible shaft including agroove therein and wherein said machine further comprises first andsecond fluid-operated means each including extensible shaft means forengagement with the respective groove for releasably latching saidshafts in their extended positions.
 3. The machine according to claim 1,wherein said means for rotatably supporting the tube comprisesarcuate-shaped means pivotally carried on said frame for receiving thetube, first wheels carried by said arcuate-shaped means, second wheelscarried by said frame, the tube being placed in rotatable engagementwith said first and second wheels when said arcuate-shaped means ispivoted to place the tube in a working position, and means forreleasably latching said arcuate-shaped means at the working position ofthe tube.
 4. A machine for making tubular projectiles from a hollowcylindrical tube, comprising: a frame; means carried on said frame forrotatably supporting the hollow tube; means for rotating the hollowtube; first and second mandrel means carried on said frame includingrespective first and second extensible mandrels and means for extendingsaid first and second mandrels into the interior of the tube, said firstand second mandrel means each comprising an extensible shaft mounted onsaid frame for reciprocal movement; and a formed mandrel head rotatablycarried by its respective shaft, said first formed head including a pinwhich extends toward the second formed head, and said second formed headincluding a bore therein for receiving said pin when said shafts areextended, said first and second heads and said pin defining the desiredinner form of said tube; third mandrel means carried on said frameincluding at least one third mandrel disposed externally of the tubeadjacent the extended position of said first and second mandrels; meansfor forcing said third mandrel against the tube section between saidfirst and second mandrels to deform the tube section; and means forcontinuously urging the ends of the tube toward each other duringdeformation of the tube to provide a constant wall thickness of the tubein the deformed section.
 5. The machine according to claim 4, whereinsaid third mandrel includes a shaped surface which conforms to the shapedefined by said first and second heads and said pin.
 6. A machine formaking tubular projectiles from a hollow cylindrical tube comprising: aframe; means carried on said frame for rotatably supporting the hollowtube; a pair of first fluid-operated means carried on said frame, eachof said first fluid-operated means including a hollow extensible shaftdirected toward the hollow extensible shaft of the other and a hollowtoothed wheel rotatably secured to the hollow shaft, the ends of thetube being engaged by the teeth of the wheels for mutual rotationtherewith; means for rotating said tooth wheels; a pair of mandrelscarried on said frame with their axes in co-axial alignment with thelongitudinal axis of the tube and each of said mandrels directed towardthe other and extending through respective ones of said hollow shaftsand toothed wheels, and including a shaft mounted for reciprocalmovement along its axis, a formed head and means for cooperableengagement of said heads; a pair of second fluid-operated actuatorscarried by said frame and including respective extensible shaftsindividually connected to separate ones of said mandrel shafts forreciprocal movement of said mandrel shafts; means for releasablylatching said first and second mandrel shafts with their respectiveheads positioned adjacent one another within the tube; and means forminga third mandrel adjacent said first and second mandrel heads on theexterior of the tube carried by said frame, said third mandrel formingmeans including a pair of lever means pivotally connected to said frame,at least one wheel rotatably carried by each of said level means withthe axis of rotation of the wheels being generally parallel to thelongitudinal axis of the tube, and means for pivoting said lever meansand forcing said wheels against the rotating tube to spin from thematerial in the contacted area into a shape defined by said first andsecond heads and said wheels.
 7. A machine for making tubularprojectiles from a hollow cylindrical tube according to claim 6 whereinsaid means for pivoting said lever means comprises third fluid-operatedmeans including a body section connected to one of said lever means anda shaft extensible from said body second connected to the other of saidlever means to operated said lever means in a scissor-like manner.